PhD position in Nanoscale Rock Magnetism and Magnetic Imaging

The Department of Earth Sciences is looking for a highly motivated PhD candidate with a MSc background in Earth Sciences or another appropriate field. You will work on the project “Nanoscale Rock Magnetism and Magnetic Imaging”. Your job This study is part of the ERC Consolidator project SPARK, which aims to unlock magnetic information stored in nanoscale vortex-state particles in rocks and other geological materials. These tiny particles may preserve key information on the strength and behaviour of the geomagnetic field during critical periods in Earth’s history, such as the early Earth, the great oxygenation event, and step-changes in the evolution in the Devonian and Ediacaran. Despite their potential, the recording behaviour and long-term magnetic stability of these vortex-state particles are still poorly understood. In this project, you will experimentally investigate which vortex-state particles are reliable recorders of the Earth’s magnetic field and how to obtain the crucial information hidden within them. Your research will focus on the empirical characterization of individual magnetic particles, combining state-of-the-art magnetic imaging with advanced electron microscopy techniques. You will generate high-quality experimental datasets that form the basis for data-driven micromagnetic modelling developed within the project. Your main tasks and responsibilities include:

• Acquiring nanoscale magnetic measurements using Quantum Scanning Microscopy and wide-field Quantum Diamond Microscopy.
• Characterizing particle geometry in three dimensions using slice-and-view FIB-SEM analysis.
• Determining mineralogical and chemical properties (composition, zoning, crystallographic orientation) using complementary electron microscopy techniques.
• Working closely with a postdoctoral researcher to use your experimental observations as constraints for micromagnetic simulations, systematically assessing how size, shape, and mineralogy control magnetic stability.
• Presenting your findings at international conferences and publishing in peer-reviewed journals.

You will be supervised by Dr Lennart de Groot and work closely with a postdoctoral researcher, who focuses on the data-driven development of micromagnetic modelling tools, as well as with a PhD candidate focusing on the paleomagnetic information stored in (statistical) ensembles of vortex-state particles. Together, you will integrate experimental observations and computational modelling to establish a robust framework for identifying which vortex-state particles reliably record the Earth’s magnetic field. The project is embedded in the Paleomagnetic Laboratory Fort Hoofddijk, which hosts two Quantum Diamond Microscopes and a Quantum Scanning Microscope, enabling magnetic imaging at spatial resolutions from micrometres down to the nanometre scale. Advanced FIB-SEM facilities are available at Utrecht University’s Electron Microscopy Center. The project further benefits from excellent dedicated CPU and GPU computing infrastructure to support large-scale numerical modelling and data analysis. You will receive extensive training in these techniques as part of your PhD project and will work in an international, multidisciplinary research environment. At the start of your PhD, a personalised training programme will be established reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes following courses/workshops as well as training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University. Your qualities You must have completed an MSc degree in Earth Sciences or a related discipline by the time the position starts (September 1st, 2026 at the latest). A background in paleomagnetism, mineralogy, and petrography through BSc and MSc coursework or research projects is highly valued. Proficiency in spoken and written English is essential. Preferably, you will also have:

• Experience with, or a strong interest in, advanced laboratory techniques such as magnetic imaging, optical microscopy, (FIB-)SEM analysis, or microCT.
• Some experience with scientific programming (e.g., Python) and willingness to further develop these skills.
• Strong motivation to work collaboratively in a diverse, multidisciplinary research team working in the interface between paleomagnetism, petrology, and mineralogy.

Non-Dutch MSc diplomas may be subject to specific approval by the Board for Conferral of Doctoral Degrees before a candidate can be accepted into the PhD programme. We strongly encourage applications from candidates with diverse backgrounds and career paths who are enthusiastic about this position. Our offer We offer:

• a position for 1 year, with an extension to a total of four years upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period.
• a working week of 36 - 40 hours and a gross monthly salary between € 3.059 and €3.881 in the case of full-time employment (salary scale P under the Collective Labour Agreement for Dutch Universities (CAO NU));
• 8% holiday pay and 8.3% year-end bonus;
• a pension scheme, partially paid parental leave and flexible terms of employment based on the CAO NU.

In addition to the terms of employment laid down in the CAO NU, Utrecht University also offers a range of its own schemes for employees. This includes arrangements for professional development, various types of leave, and options for sports and cultural activities. You can also tailor your employment conditions through our Terms of Employment Options Model. In this way, we encourage you to keep investing in your personal and professional development. For more information, please visit Working at Utrecht University. About us A better future for everyone. This ambition motivates our scientists in executing their leading research and inspiring teaching. At Utrecht University, the various disciplines collaborate intensively towards major strategic themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Pathways to Sustainability. Sharing science, shaping tomorrow. Utrecht University’s Faculty of Geosciences studies the Earth: from the Earth’s core to its surface, including man’s spatial and material utilisation of the Earth – always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development. The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. Our key research themes are Earth & Planetary Processes, Sustainable Use of the Subsurface, Planetary Health & Environment, and Climate & Life. The department hosts a highly international tenured staff. Besides the Paleomagnetic Laboratory, we house or have access to a wide variety of world-class laboratories, among which are UU’s Electron Microscopy Centre, the Geolab, and the Earth Simulation Lab. We also have excellent High- Performance Computing facilities and organise a warm welcome for every new member. More information For more information (not for application) about this position, please contact Dr Lennart de Groot at l.v.degroot@uu.nl. Candidates for this vacancy will be recruited by Utrecht University. Apply now As Utrecht University, we want to be a home for everyone. We value staff with diverse backgrounds, perspectives and identities, including cultural, religious or ethnic background, gender, sexual orientation, disability or age. We strive to create a safe and inclusive environment in which everyone can flourish and contribute. Knowledge security screening can be part of the selection procedures of academic staff. We do this, among other things, to prevent the unwanted transfer of sensitive knowledge and technology. You can only apply via our online application system using the 'Apply now' button. Applications submitted by email cannot be considered. Please include the following documents with your application:

• A letter of motivation, describing why this PhD position fits your background and interests. Please also explain why you are interested in working at Utrecht University’s paleomagnetic laboratory Fort Hoofddijk.
• A curriculum vitae, including relevant experience from your BSc and MSc courses and research projects. Keep in mind that experience outside academia in e.g. voluntary positions may also illustrate your capacities for this position.
• Academic transcripts (mark sheets and degree statements) as far as already available and relevant.
• The names and contact details (including email addresses) of at least two referees.

No reference letters are required at the time of application. If you are shortlisted, we will contact your referees, but only after informing you in advance. We aim to complete the selection procedure shortly after the application deadline of 15 February 2026. Interviews are expected to take place in calendar weeks 9, 10, or 11, and the initial interview may be conducted via video call or in person. However, before a final offer is made, an in-person meeting at Utrecht University and the paleomagnetic lab Fort Hoofddijk is required. The starting date can be as soon as 1 April 2026 (administration permitting), or as late as 1 September 2026. If you have an international (non-Dutch) Master’s diploma, you will be requested to provide your Bachelor’s and Master’s diplomas as well as the corresponding grade lists (in English) if you are selected for this position. Note that international candidates that need a visa/work permit for the Netherlands require at least four months processing time after selection and acceptance. This will be arranged with help of the International Service Desk (ISD) of our university. Finding appropriate housing in or near Utrecht is your own responsibility, but the ISD may be able to advise you therewith. Unfortunately, we must warn that it is a tight market at the moment. In case of general questions about working and living in The Netherlands, please consult the Dutch Mobility Portal. Online screening may be part of the selection. Commercial response to this ad is not appreciated.